1 files changed, 81 insertions, 0 deletions
diff --git a/chromium/net/spdy/spdy_prefixed_buffer_reader.cc b/chromium/net/spdy/spdy_prefixed_buffer_reader.cc
new file mode 100644
index 00000000000..8a4638c3140
--- /dev/null
+++ b/chromium/net/spdy/spdy_prefixed_buffer_reader.cc
@@ -0,0 +1,81 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/spdy/spdy_prefixed_buffer_reader.h"
+
+#include "base/logging.h"
+
+namespace net {
+
+SpdyPrefixedBufferReader::SpdyPrefixedBufferReader(
+    const char* prefix,
+    size_t prefix_length,
+    const char* suffix,
+    size_t suffix_length)
+    : prefix_(prefix),
+      suffix_(suffix),
+      prefix_length_(prefix_length),
+      suffix_length_(suffix_length) {}
+
+size_t SpdyPrefixedBufferReader::Available() {
+  return prefix_length_ + suffix_length_;
+}
+
+bool SpdyPrefixedBufferReader::ReadN(size_t count, char* out) {
+  if (Available() < count)
+    return false;
+
+  if (prefix_length_ >= count) {
+    // Read is fully satisfied by the prefix.
+    std::copy(prefix_, prefix_ + count, out);
+    prefix_ += count;
+    prefix_length_ -= count;
+    return true;
+  } else if (prefix_length_ != 0) {
+    // Read is partially satisfied by the prefix.
+    out = std::copy(prefix_, prefix_ + prefix_length_, out);
+    count -= prefix_length_;
+    prefix_length_ = 0;
+    // Fallthrough to suffix read.
+  }
+  DCHECK(suffix_length_ >= count);
+  // Read is satisfied by the suffix.
+  std::copy(suffix_, suffix_ + count, out);
+  suffix_ += count;
+  suffix_length_ -= count;
+  return true;
+}
+
+bool SpdyPrefixedBufferReader::ReadN(size_t count,
+                                     SpdyPinnableBufferPiece* out) {
+  if (Available() < count)
+    return false;
+
+  out->storage_.reset();
+  out->length_ = count;
+
+  if (prefix_length_ >= count) {
+    // Read is fully satisfied by the prefix.
+    out->buffer_ = prefix_;
+    prefix_ += count;
+    prefix_length_ -= count;
+    return true;
+  } else if (prefix_length_ != 0) {
+    // Read is only partially satisfied by the prefix. We need to allocate
+    // contiguous storage as the read spans the prefix & suffix.
+    out->storage_.reset(new char[count]);
+    out->buffer_ = out->storage_.get();
+    ReadN(count, out->storage_.get());
+    return true;
+  } else {
+    DCHECK(suffix_length_ >= count);
+    // Read is fully satisfied by the suffix.
+    out->buffer_ = suffix_;
+    suffix_ += count;
+    suffix_length_ -= count;
+    return true;
+  }
+}
+
+}  // namespace net